The present big warm air invasion has its origins in the Pacific Ocean. There, a large high pressure system over the Bering Sea is facing off with a strong low moving up across Kamchatka. Running between the two is a powerful south-to-north wind pattern.

(A major warm wind invasion of the Arctic on Thursday is originating in the subtropical Pacific. A ridge in the Jet Stream extending all the way to the North Pole is pulling this big bulge of warm air north. As a result, extreme temperature departures and out of season sea ice melt for the impacted zones are likely. Image source: Earth Nullschool.)

As we can see in the image above, the flood of warm air has its origin around the 30 north latitude line. It flows directly over hundreds of miles of ocean, at times reaching a storm-force intensity near 70 mph. As it crosses into Siberia, the wind slows down. But it inexorably continues north, ever north — driven on by a serious pulse of atmospheric steam. By early Thursday, the leading edge of this warm air outburst from the Pacific side will have crossed the Pole and led to a flushing of Central Arctic air out into the Barents Sea and North Atlantic (you can view an animation of the predicted warm air pulse here).

This strong northward flood of warmth from the Pacific is running up under an extreme high amplitude wave in the Jet Stream that is bellowing out into the Arctic Ocean through the Bering and Chukchi seas. At its peak northward extent, the big Jet Stream wave is predicted to look something like this. And it is this severe contortion in the upper level wind pattern that has enabled this most recent extreme warm wind event to occur.

This pattern is now in the process of injecting above-freezing air temperatures into Eastern Siberia. By tomorrow, the warm air mass will encounter the coastal regions of the Chukchi and East Siberian seas. There, it will push temperatures as high as 2.5 C (37 F) over zones that typically see readings in the -20s to -30s (Celsius). As a result, temperatures will range between 20 and 30 C (35 to 55 F) or more above average for many locations.

(Climate Reanalyzer has added a new color — white — for tracking extreme departures in temperature. In the positive anomaly column, we find departures hitting 30 C, or 54 F, above average for regions of East Siberia and the local Arctic Ocean.)

To be clear, these temperatures are highly abnormal. If a similar temperature departure happened in Gaithersburg, Maryland on December 8, it would produce 80 to 100 degree (F) readings. Of course, this anomaly is not happening in Gaithersburg. Due to a global warming related process called polar amplification in which the poles are more sensitive to alterations in rising greenhouse gas levels (due to fossil fuel and related emissions), extreme temperature anomalies tend to occur at the poles as rates of relative warming are 2-3 times faster in those regions. And the factors that we observe associated with this new Arctic warm wind event — powerful south-to-north meridional air flows coupled with extreme high amplitude waves in the Jet Stream — are also evidence of a number of weird new atmospheric circulation patterns that can tend to pop up as polar amplification intensifies.

Warm Winds May Cause Unprecedented Back-to-Back Fall Sea Ice Melt

The Pacific side of the Arctic has already been gaining heat ahead of the oncoming warm wind event over the past few days. And what we have seen, as a result, is a pretty severe loss of ice in the Chukchi Sea during early December. To be very clear, Arctic sea ice should be advancing at this time of year. But what we see in the image below (provided by A-Team over at the Arctic Sea Ice Forum) is advance followed by retreat as the warm wind event starts to ramp up.

(Ice refreeze in the Chukchi advances until it is rolled back by the most recent onrush of warm air flowing in from the Pacific. Image provided by A-Team at Neven’s Arctic Sea Ice Forum.)

Of course, the retreat seen above has occurred before the main force of warm southerly winds — due to hit the Arctic Ocean region by tomorrow. So the risks for continued losses in the Chukchi extend for at least the next few days. Losses there could be offset by large enough gains elsewhere to continue an overall seasonal freeze trend. But so far, with abnormal warmth also periodically building in over the near-Svalbard region and with Hudson Bay refreeze continuing to lag, that does not appear to be happening.

Looking at the larger monitors, we also find that, as happened during October and November, the pace of overall sea ice growth has stalled. According to JAXA, over the past 4 days, sea ice extent has only grown by 50,000 square kilometers. During a typical similar four day period for this time of year, growth would tend to average around 400,000 to 500,000 square kilometers. And with values at current record low levels, the inertial impetus for ice growth would be higher. That is, unless the climate state of the Arctic has radically changed — which appears to be the case.

(According to JAXA, Arctic sea ice extent has again hit a plateau when it should be freezing — this time at around 10 million square kilometers. As sea ice follows that line, record lows are again deepening — hitting near 750,000 square kilometers below previous lows for the day in 2006. Considering the fact that another major warming event is building into the Arctic Ocean, this plateau could again tip into melt as happened during the middle of November. Image source: JAXA.)

During mid November, a period of unprecedented warming produced an almost unprecedented period of fall melt. A similar November melt occurred during 2013. But the amount of melt then was smaller. And that melt did not occur at a time when Arctic sea ice values were at new record lows — as they were throughout the entire month during 2016. Similarly, during October, abnormally warm conditions produced an odd re-freeze plateau similar to the one we are now experiencing.

Given current conditions, there’s a risk that we could see a December melt event following the November melt event. For the amount of heat hitting the Pacific side of the Arctic is predicted to fall far outside of normal temperature ranges. And, barring major refreeze on the Atlantic side, we are at a rather higher risk of seeing the present plateau in sea ice values carry on for a number of days.

It didn’t take long for Arctic sea ice to start to respond to a fossil-fuel based accumulation of hothouse gasses in the Earth’s atmosphere. For since the 1920s, that region of ocean ice along the northern polar zone has been in a steady, and increasingly rapid, retreat. Rachel Carson wrote about the start of the Northern Hemisphere ocean ice decline in her ground-breaking 1955 book — The Edge of the Sea.

It’s a warning that has been written in the record of the ice itself. A decline that since 1979 has followed a steepening descent curve. An overall downward trend punctuated by the abrupt and severe loss years of 2007 and 2012. A trend that has, nonetheless, featured a few weak challenges in the form of pseudo-recovery years like 2008, 2013, and 2014. A precipitous loss that, all too soon, will likely terminate with abrupt finality in temporally-expanding blue ocean events. Periods when little or no sea ice is observed on the surface of oceans and seas within the Arctic.

(After the warmest Winter and early Spring period on record, Arctic sea ice extent, area and volume are now at or near new record lows. With abnormal heat persisting and with the ice showing an extraordinary lack of resiliency, there appears to be a heightened risk that Arctic sea ice will hit new record all-time lows by September and October of 2016. Image source: JAXA.)

Why should we talk about blue ocean events now? Well, we have only to look at the sea ice record to find that substantial losses have occurred during single years. Years when Arctic heat hit new peaks — lining up with severe adverse weather conditions to take a terrible toll on the ice. Years like 2007 when nearly 2 million square kilometers of ice was lost over the previous year and 2012 which featured about 800,000 square kilometers of extent lost below the 2007 low mark. And if a blue ocean event does happen, it will be during one of these severe loss years.

Extremely Frail Sea Ice During the Spring of 2016

2016 and 2017 could be years when such precipitous declines occur. Heat from an extraordinarily powerful El Nino already skipped over the weakening atmospheric wall of the Jet Stream to invade the High Arctic during Winter of this year. As a result, Winter and Springtime Arctic temperatures are currently at their warmest levels ever recorded.

All this extra heat is doing a number on the ice. Sea ice extent, volume and area, which had experienced a false recovery during the years of 2013 and 2014, have again retreated to seasonally record low levels. In particular, the new near record low seasonal volume measure is disturbing. For while area and extent measure the expanse of surface ice as visible from above, volume measures the ice in three dimensions — giving a better idea of overall resiliency or lack thereof. It’s worth noting that the PIOMAS volume measure is based on a model of assimilated observational data. And, as with any model, there are a few assumptions built in. But overall, PIOMAS has tended to provide data that has matched with other observational findings.

Sea ice frailty seen in the measures is also verified by current satellite observations of the ice surface. This frailty is particularly visible in the region of the Beaufort Sea north of Alaska and Canada. There, extensive fracturing of the ice is clearly visible in yesterday’s MODIS satellite shot. Here we find huge regions of thin ice and open water as the torquing influence of a powerful high pressure system has turned the greatly weakened Beaufort ice into a sea of ice cubes.

During recent years in the post 2012 timeframe, Beaufort ice has shown a considerable lack of resiliency to fracturing. This is particularly disturbing as, historically, the Beaufort Sea has tended to house the thickest, toughest ice in the Arctic. If such a great former bastion for the ice can now be torn to ribbons by the slightest fluxes of wind and weather, then the sea ice is, indeed, in a rather wretched state. And last year, just this kind of early fracturing and warm up in the Beaufort greatly contributed to an overall return to the trend of an Arctic sea ice death spiral in 2015.

Last year’s April cracking event caused a lot of fragmented multi-year ice to be transported all the way up to the Chukchi Sea (see here), leaving a vulnerable looking barrier on the Pacific side of the Arctic. When this was followed by an early heat wave in May (see here), the ice in the Beaufort and Chukchi Seas received a beating it never really recovered from during the rest of the melting season. This was also because continental snow had melted out really quickly, making it possible for warm winds to blow in from the land.

Heating From Both Water and Land

Compared to last year, this year looks quite a bit worse. A wide-ranging Beaufort break-up is happening on the back of last year’s losses and is concurrent with new record and near record low sea ice extent, area and volume values and is happening during a period in which Arctic heat has hit new all-time highs. The result is a risk of compounding melt factors hitting the greatly weakened ice all at the same time.

Locally, the kind of widespread fracturing we now observe can result in a loss of protective reflectivity for the sea ice. As the Springtime sun rises and more of its direct rays fall upon the ice, darker thin ice patches and areas of open water will absorb more of the solar heat. That extra heat will then go to melting the islands of thicker ice that remain.

This situation can generate a compounding effect of ice losses if weather conditions and atmospheric temperatures line up. In addition, loss of the thicker sea ice cap during break-up can result in the ventilating of heat from the warmer waters beneath the ice. In fact, it is the heating of waters beneath the sea ice by means of current transport of warming ocean waters from around the world and into the Arctic that is one of the chief drivers of Arctic Ocean ice losses as the globe has been forced to warm by human fossil fuel emissions. So not only does an ice crack up in the Beaufort reduce the ice’s resiliency to the sun, it also tears the lid off the deeper ocean warming rising up from below.

(Lower albedo due to ice fracturing results in more of the sun’s rays being absorbed into the ocean surface. A warmer Arctic Ocean surface then radiates more heat into the surrounding environment. Such conditions can result in periods when temperatures over the, previously colder and solidly frozen, Arctic Ocean are far warmer than even over land masses on the verge of tipping into a springtime thaw. Image source: Earth Nullschool.)

During Arctic Spring, when land surfaces are now retaining snow cover even as the sea ice breaks up, the effect of lower albedo and ocean heat ventilation can be found in the form of warmer temperatures over thin ice, broken ice, and in open water regions when compared to nearby land masses. Such a condition of newly added heat over ocean zones can have substantial impacts come Summer if melt-favorable weather patterns continue to hold sway. The result is a kind of melt synergy developing between the land, the waters, and the sun. Early on, during Spring, the warmer ocean zone weakens ice and provides warm air pools that aid in the initiation of snow melt over adjacent land. Then, as land warming ramps up, the warm winds coming from regions of early snow withdrawal provide further pressure to the already greatly weakened ice.

A Big Burly High as the Final Ingredient

Weather patterns that favor melt during Spring and Summer include powerful high pressure systems dominating large regions of the Arctic. And for much of the past week, an extremely intense high in the range of 1040 to 1045 mb has stooped over the Beaufort, torqued the ice, and developed the kind of strong clockwise wind flow that has tended to result in fracturing, ice compaction, and the opening of darker ice and open water areas (please read Neven’s fantastic recent blog on this observation here).

This kind of weather system is the last ingredient necessary to trigger an early, rapid melt for the side of the Arctic where the last of the thick, old ice now remains. And it appears that, for at least two weeks, such conditions will hold strong sway over the Beaufort.

So overall, more and more conditions are lining up to deliver a ramping up of melt pressure on the Arctic sea ice. Record atmospheric heat, early break-up, record low or near record low area, extent, and volume, and a powerful high pressure system over the Beaufort do not at all bode well. In fact, this looks like a near perfect early season set-up for a record melt in 2016 should this clearly ominous trend continue.

These days — in the age of the fossil-fueled hothouse — it’s never good news when a high pressure system forms over Greenland during Summer.

Human dumping of carbon into the atmosphere has forced warming over the last remaining great Northern Hemisphere ice sheet at a rate of about 0.5 degrees Celsius each decade. A constant rain of soot from human industry and from increasingly prevalent and intense Arctic wildfires has painted the ice sheet dark, lowering its ability to reflect 24 hours of incoming radiation from the Summer sun. And the result is that each Summer, when the skies clear and high pressure systems form over the ailing Greenland ice, you end up getting these huge surface melt spikes.

(Smoke from record Alaskan and Canadian wildfire outbreaks traverses Greenland and enters the North Atlantic on July 2 of 2015. Arctic wildfires are intensified by human-caused warming both through the mechanism of added heat and through the reintroduction of long sequestered carbon fuels through permafrost melt which aids in the initiation, intensification and extension of Arctic wildfire burn periods. In essence soil carbon in the form of thawed permafrost and related methane adds to boreal forest, tundra and bog as burn risks. Soot from these fires can then precipitates onto land and sea ice, reducing its ability to reflect the 24 hour Summer Arctic sun. Image source: LANCE MODIS.)

Generally a big melt spike can be defined as anything greater than 35 percent of Greenland ice surface area. And we’ve had quite a few of these abnormal events in recent years. The worst of which happened in mid Summer of 2012.

During late June and early July of that year, an extreme high amplitude Jet Stream wave generated very warm surface temperatures over the Greenland Ice Sheet. A very warm fog settled over the ice, eating away at it. By July 8th, more than 90 percent of the surface was melting — an event that hasn’t happened in Greenland for more than 100 years. June, July and August of 2013 and 2014 saw similar, though somewhat less intense, Greenland melt spikes. During those years the ice sheet experienced multiple days in which melt covered between 35 and 45 percent of its surface. And though these instances were not as intense as the unprecedented 2012 melting, they did traverse well beyond the 1981 to 2010 average line (an average that itself includes a rapid warming trend) to, in cases, exceed the upper 2 standard deviation margin.

(Record Greenland surface melt during 2012 compared to still strong surface melt years of 2013 and 2014. Image source: NSIDC.)

After record 2012 melt, surface melt for Greenland has remained abnormally high — indicating an increased likelihood that more near 100 percent surface melt summer days may not be too far off in the future. The post 2012 environment for Greenland has thus been a period of continued and heightened surface melt. One that appears to be in the process of building up to another big pulse.

50 Percent Melt Threshold Exceeded During July of 2015

The summer of 2015 marks a continuation and intensification of this ominous surface melt trend. After getting off to about an average melt start during April and May, June saw surface warmth build over the Greenland Ice Sheet with melt extents jumping to between 30 and 40 percent of surface area by mid-to-late month. Further warming coincided with massive Alaskan and Canadian wildfires injecting soot plumes into regional airspace and the building of a substantial high pressure ridge over Greenland. These factors helped enable further atmospheric and ice warming — shoving surface melt above the 50 percent line by July 4th.

This puts 2015 Greenland surface melt in a range well above 2013 and 2014, with the first week of July already exceeding 2012 melt for that period.

Over the next seven days, models predict a larger warming of the overall Arctic environment even as a high pressure system and associated ridge remains entrenched across Greenland. This predicted weather pattern will tend to lock in significantly warmer than 20th Century average temperatures. That said, forecast highs do not yet indicate a substantial risk for a repeat of 2012’s near 100 percent surface melt. However, projected high temperatures do show some potential that melt percentages are likely to continue to range between 40 and 60 percent surface melt over coming days with the highest risk for melt spikes occurring on July 6th, 7th and 8th.

It is worth noting that we are now in the midst of a substantial Greenland melt spike, one that we’ll continue to monitor over coming days for further developments.

It’s the end of a bad week in a bad month in a bad season in the all-too-bad, human-heated, era for Arctic sea ice. As of the middle of this week, both the US measure — NSIDC — and Japan’s measure — JAXA — were showing record low daily sea ice extents. The lowest levels in the history of Arctic sea ice observation for this time of year and likely the lowest levels for hundreds, even thousands of years.

As charts go, the JAXA graphic looks pretty amazingly ominous. A 2015 sea ice extent line diving below all others, steadily plumbing an abyss that, if not this year or the next, could lead to a dreaded blue ocean event in the not-too-distant future. The kind of upshot from human greenhouse gas emissions we thought we might see by 2080 or later. One that has become increasingly more likely during recent years and that some researchers are expecting could emerge by before 2020.

(JAXA sea ice measure plunging to new record lows on May 22 and now hitting a very steep angle of decline. Image source: JAXA Polar Research.)

Above you can seen the 2015 red line taking its most recent plunge after hovering very near to record low levels. According to JAXA’s Polar Research Center, sea ice extent dropped like a stone to 11.44 million square kilometers yesterday, or about 200,000 square kilometers lower than the previous record low value set in 2006.

Divergence in May

The problem is not just one of a new record low. It’s one of timing and divergence. Accelerated melt in the May-to-June time-frame can have serious impacts on late season ice. The reason is that greatly reduced ice coverage also reduces albedo or reflectivity. The result can be compounded warming and increased heat absorption by darker surfaces under the 24 hour Arctic sunlight of June and July.

Large open stretches of ocean also enable swell formation, which can chew away the ice. And already we can see very large sections of dark, low albedo, ocean forming throughout many vulnerable regions.

(MODIS satellite shot shows widespread regions of open ocean and far northward melt advance for this time of year. Image source: LANCE-MODIS.)

For this time of year, we have very advanced sea ice loss and open ocean development in the regions of the Chukchi, the Beaufort, Northern Baffin Bay and the Kara. In addition, large open water areas are now becoming visible in the Laptev. A far northern extent of sea ice melt for May in addition to typical seasonal losses coming from Hudson Bay and southern Baffin Bay.

Such record low ice totals at this time of year can enable far greater melt advance by end season if the weather stacks up in all the wrong ways. And, at least for the next week, the weather forecast is tilting ever more heavily toward a melt-enhancing extreme warming of Arctic regions.

Arctic Warm Air Invasion Forecast to Continue

Over the next seven days, heat is predicted to continue to flood from south to north — goaded along by high amplitude ridges in the Jet Stream continuing to form over Northwestern North America and the Siberian region adjacent to the Kara Sea. The warm flux zones are forecast to deliver unseasonable, above average temperatures to the Arctic — resulting a general state of much warmer than normal conditions for the entire Arctic Ocean by late next week.

(Side-by-side comparison of Arctic temperature anomaly forecast [left] and 2 meter temperature forecast [right] for May 29, 2015 in the GFS model run as provided and graphically displayed by Climate Reanalyzer. It’s worth noting that such extreme anomalies are very unusual for Arctic Ocean regions during late spring and summer.)

As a result, we see temperature anomalies for the entire Arctic Ocean zone hitting a range of between 5 and 15 degrees Celsius above average for next Friday (May 29, 2015). Such a warm air surge would push temperatures in the above freezing range for almost the entire Arctic Ocean area. These are temperatures more typical of late June and early July. Conditions that, should they emerge, would result in a multiplication of ice-threatening melt ponds, a further expansion and warming of already unseasonably large open water zones, and a forcing of more ice-eating, high heat content water vapor into the Arctic environment.

Any forecast is subject to uncertainty. Rapid May melt during 2013 and 2014 stalled out during June of those years. However, May melt is significantly more advanced this year than during those years. And, as opposed to 2013 and 2014, GFS model forecasts showing warmer than normal conditions have tended to be correct. The warm air slots over Northwest North American and Western Siberia are also very well established at this time.

As a result, there’s high risk that the current record lows now appearing in the NSIDC and JAXA measures with continue to deepen over the coming week. It’s an utterly wretched situation for sea ice in the Northern Hemisphere. One that will bear very close watching as the risks now appear to be heading toward some unsettling markers.

On March 4, amidst a building polar heat amplification and a strong, thousands mile long, south to north wind and storm flow across the North Atlantic and into the Arctic, sea ice extent coverage for the northern polar region plunged to new record lows.

(26 foot wave heights [left frame] and 50-60 mph sustained southerly winds [right frame] in conjunction with warm storm near the ice edge at Svalbard on March 15, 2015. Storms of this kind have been raging up through the Barents delivering powerful, warm southerly winds and immense swells to the ice edge region for at least the past half month. This strong melt pressure and warm air delivery has contributed to record low sea ice extent totals continuing for the past 13 days running. Image source: Earth Nullschool. Data source: GFS.)

Human-forced heat continued to build throughout the Arctic as warm and intensely windy storms churned northward through the Barents, bringing with them powerful swells ranging from 15 to, at times, 40 feet in height. As these great swells ground away at the ice edge, temperatures hit daily anomalies greater than 4 C above the 1979-2000 average on Sunday, March 8 for the entire Arctic region. The next day, sea ice extent, according to NSIDC, plummeted to 14,273,000 square kilometers. A value 303,000 square kilometers, or an area about the size of Arizona, smaller than the previous record low value for the date set in 2006.

Ever since March 4, the Arctic has remained in new record low territory — a period that has now lasted 13 days. Though anomalous warmth has faded somewhat — dropping today to a range of 2.65 degrees Celsius above the 1979-2000 average — sea ice has only bounced back slightly. On March 15, the NSIDC extent measure had inched up to 14,333,000 square kilometers, still about 235,000 square kilometers below the previous record low for the date.

(Arctic sea ice extent as measured by NSIDC drops below previous record low values on March 4 of 2015 [bottom dark blue line] and has remained at record low levels ever since. For reference, previous record low years for March dates include 2006 [pink line], 2007 [light blue line], and 2011 [orange line]. The top dark blue line [1979] indicates how much sea ice extent has been lost during March over the past 36 years. Image source: NSIDC.)

Over the next week, however, these new record lows are more likely to continue to fade as warm Arctic surface temperature anomalies drop to around 1-2 C above average, the Arctic Oscillation shifts toward neutral or slightly negative, and the warm storm track through the Barents is interrupted by cold winds pushing south toward Scandinavia from the pole. Although mid-week warming forecast for Alaska and Baffin Bay may retard any potential rebound somewhat.

For the past two years, Arctic sea ice has experienced a bit of a rebound during the March through early April time-frame. This has appeared to coincide with a restrengthening of the polar Jet Stream as mid latitudes have warmed which, in turn, has weakened meridional patterns transporting heat into the Arctic during winter time. Low angle sunlight entering the Arctic at this time of year has also not yet gained enough momentum to significantly push the ice to melt. So we still have about a 2-3 week window for potential bounce-back before sunlight builds and begins to apply its steady heat forcing to the greatly diminished ice.

(Arctic Oscillation [AO] index forecast shows dip toward slightly negative or neutral AO status by end week after a rather extreme high in early March, with a return to mildly positive AO values by end month. Positive AO enhances edge melt of sea ice by encouraging storm formation at the ice edge and warm air invasions over the central ice. Image source: NOAA/CPC.)

That said, the ice is quite frail now, even with potential volume rebounds to mid 2000s levels. So even the slight addition of solar insolation may be enough to keep ice coverage values depressed in the neutral or moderately positive Arctic Oscillation regime that is predicted through the end of March. Extent measures maintaining near record lows along the 2006, 2007 and 2011 tracks, or just below, would establish a very low launching pad for a melt season that, lately, has tended to include precipitous declines in ice during the summer months.

The ongoing record low extent status, despite a return to weather patterns that are more favorable for rebound or maintenance, therefore, should be closely monitored.

2012. It may not be the year the world ended. But it will, likely, be the year we came to terms with the eminent and tragic final days of Arctic sea ice.

It began innocuously enough. Five years after the record losses seen in 2007, there was some cause for hope of a slower, more gradual decline. Most 2007 records had held with 2011 seeing only a slight drop in the sea ice area measurement. Though it was obvious calls for sea ice recovery were entirely unfounded, there was little reason to suspect another season of violent losses like that seen during 2007. The weather was predicted to be unfavorable for a record melt and, at most, minor losses were expected.

What unfolded was a sea ice Armageddon of massive scale. A freakish loss that defied all conventional expectation of weather and climate. For most of the summer, conditions favored a spreading out of the ice sheet. This condition usually enhanced the resiliency of sea ice, keeping the reflective coating over a larger area and, therefore, driving temperatures down.

But, this year, it was apparent the sea ice had spread out too much, had grown too thin. A rotten film filled with holes and encircled by an invading mass of warmer winds and seas. An ice screen vulnerable to the assault of sun, wind, and wave in a way that the Arctic sea ice had never been vulnerable. Not in our history, at least. Not in that thin span measuring our frail and short-sighted civilization.

That blow came during late August in the form of a powerful storm. The Great Arctic Cyclone of 2012.

Spawning in the burning Siberian Arctic, this storm formed in a region where massive blazes had, only a month before, belched out enough smoke to cover Canada’s valleys, thousands of miles away. Latent heat and moisture had concentrated there, building and building through an unnaturally long and hot summer season.

Like a hurricane, its clouds towered, marching out with gathering strength to assault the frail and weakened ice. The giant storm howled, sending 65 mile-per-hour winds through the Chukchi Sea, and aiming its fury strait at the Arctic’s heart. It dug deep from heat and moisture reserves to the south, a source of energy only recently made available by human-caused warming. And it spent that new-found might in a mountainous blow against the desperately weakened ice. Waves of 6, 8, 12 feet roared over the thinly frozen sea, breaking it into a slurry and mixing it with the warmer surrounding ocean as if in an enormous blender. When The Great Arctic Cyclone of 2012 finally died out somewhere near the North Pole, hundreds of thousands of square miles of sea ice had been churned up, spit out, melted.

From our perch high above the Earth, from our lookout through the Japanese Space Agency‘s satellite eye, the sea ice just prior to the week-long Great Arctic Cyclone of 2012 looked like this:

And, afterward, most of the ice in the vast Chukchi Sea had been cleared away. Melted in the storm’s fury or pushed deep into the high Arctic, driven against that final buttress for northern ice: Greenland.

But the story of 2012’s deadly melt was far from over. The now thinned and storm-weakened ice continued its daily decline for more than a month after the ravages of The Great Arctic Cyclone of 2012 abated, finally reaching a state far, far weaker than even the terrible year of 2007. It left the Arctic with about half the ice coverage seen during the 1980s. An ice coverage that is now also far, far thinner.

What we can take away from the sea ice’s decline since the 1980s and its telling year of violent and freakish loss in 2012 is a simple message:

The ice will be gone soon. The only question is how soon.

A Tale of Loss By the Numbers

In answering the question of how soon the last small remnant of Arctic sea ice will vanish, victim to the powerful forces our human world has set loose upon it, we should take a look at the numbers, at what we know has come before, and at where the trends are leading.

In taking this final remnant of ice into account, we have three measures. They include sea ice extent, sea ice area, and sea ice volume. Each measurement has its own tale to tell and each tale can give us some idea as to when sea ice will finally fail — first at the end of summer, and last for all time and for all seasons.

The Tale of Sea Ice Extent: Jack Frost’s Shrinking Arm

Sea ice extent is a measure of how far the sea ice edge reaches. If we take the border of the continuous outward edge of the polar ice and draw a line around it, all regions within that circle are counted as part of sea ice extent. Extent does not count holes in the ice. So this measurement may include some open water areas behind the extent border.

Up until 1979, our best observations for sea ice extent came from reports collected by ships. But even these spotty accounts were enough to show a slow, long-term decline in sea ice since the early 20th Century. What satellite measurements did was make sea ice extent and area measures far more accurate.

In 1979, sea ice extent measured 7.2 million square kilometers according to the first measurement set collected by the National Snow and Ice Data Center (NSIDC). Final sea ice extent for end of 2012 was 3.6 million square kilometers. A visual graph of this 33 year decline was composed by Larry Hamilton and can be seen here:

As you can see from the graph, sea ice extent slowly retreated through the 1970s and 1980s. The 1990s showed substantial average losses. But the rate of loss was still relatively slow. Even the early 2000s, when looking at extent measures alone, doesn’t give us any clear indication that we are on the verge of a rapid, violent decline. It is not until the period of 2005-2012 that we begin to get a hint that something devastating is afoot with 2012 putting a final full stop on a period of melt that has resulted in the loss of half the Earth’s northern sea ice extent.

Final numbers for sea ice extent losses since 1979:

3.6 Million Square Kilometers of Sea Ice Extent Lost

50% of Arctic Sea Ice Extent Lost

A 50% loss of sea ice in so short a period is a devastating reduction in the reach of the world’s frozen regions. If Jack Frost were to serve as a metaphor for the sea ice, we’d say his arms had been cut in half.

Sea ice extent gives us our least detailed picture of ice loss. Since it only measures the edge of ice, we don’t really know what’s going on behind the ice margin. And that’s where looking at sea ice area comes into play.

The Tale of Sea Ice Area: Frozen Swiss Cheese

If sea ice extent draws a circle around the ice pack’s leading edge, then sea ice area tries to take into account all the visible surface ice as well as open holes behind the ice pack. Area, therefore, is the total measure of all ice as visible from above.

For sea ice area measurement, we also have data compiled by NSIDC and posted on the polar ice observatory Cryosphere Today. From these measurements, we get a picture of sea ice area decline since 1979 when area measured 5.9 million square kilometers at the end of the melt season. Cryosphere Today provides a good graph for sea ice area, measuring the progression of freeze and melt season to season, year to year:

The peaks show maximum annual sea ice area at winter’s end. The dips show the summer sea ice minimum. The red dot is showing today’s measurement.

As with sea ice extent, area remained relatively stable through the 1980s. A very gradual and slow decline began in the 1990s and extended through the mid 2000s. Then, after 2005, the bottom dropped out. A visual of the total loss seen in the graph at end of summer provides a stunning record of how much sea ice area has diminished:

By the numbers, final minimum sea ice area in 1979 was 5.9 million square kilometers. Final minimum sea ice area in 2012 was 2.24 million square kilometers.

Final losses for sea ice area since 1979:

3.66 Million Square Kilometers of Sea Ice Area Lost

62% of Arctic Sea Ice Area Lost

It is important to note that sea ice area is a more exact measurement than sea ice extent. Taking into account the holes in the ice gives us a more complete picture of the sea ice’s health. And in comparing sea ice area and extent, we can see the actual losses are much greater than the initial sea ice extent measure would have indicated. The tale of sea ice area loss since 1979 is this: a 62% drop in sea ice area since 1979 shows the Arctic ice has been reduced to little more than frozen Swiss Cheese.

But the most detailed and devastating measure of sea ice is yet to come: sea ice volume.

The Tale of Sea Ice Volume: Only a Thin Film Left

Just as it was difficult to get an accurate measure of sea ice area and extent before the age of satellites, it has been equally difficult to gain an accurate measure of sea ice volume. That is, until Cryosat data began being used just this year.

Over the past few years, however, a sea ice modeling tool known as PIOMAS (Pan-Arctic Ice Ocean Modeling and Assimilation System) has taken data observations from the Arctic (ships, planes, submarines, satellites) and plugged it into a model to get a general sense of total sea ice volume. PIOMAS data, until recently, was considered a secondary, less accurate source of Arctic sea ice information. This demotion was due to the fact that PIOMAS was only a model based on direct observations, not a direct observation itself. But the status of PIOMAS changed when an analysis of Cryosat2 data by British scientists validated the PIOMAS findings, proving the model accurate. Cryosat2 used a space-born sensor to plumb the ice and it was these measurements that validated the PIOMAS results.

When the PIOMAS results were validated, a ripple of fear passed out through the Arctic sea ice community. The reason for this dread, if you are not a habitual observer of Arctic sea ice, will grow more clear to you as you read further.

Sea ice volume is a total measurement of the ice. Its length, its width and its depth. The measure is in cubic kilometers, not the flat squares seen above as from a photograph. In short, volume tells the real story of the Arctic sea ice.

And the story is very, very grim.

The above image, provided by Larry Hamilton, takes collected PIOMAS data, and plugs it into a simple graph. If a picture paints a thousand words, then this one paints a million. For my part, I will do my best to summarize.

What the PIOMAS data in the graph reveals is that the gradual declines seen in Arctic sea ice area and extent measures were hiding a much larger trend. A trend of substantial ice loss that has been ongoing since 1979. The 1980s was not the stable decade area and extent would indicate. The 90s showed a period of rather rapid ice loss. And the 21rst century showed a tremendous and increasing pace of decline.

Any child knows that when ice melts in a glass, it grows thin first, then loses most of its surface at the end if its melt. This process is what appears to have happened with Arctic sea ice at the scale of giants.

Final losses for sea ice volume since 1979:

13,300 Cubic Kilometers of Sea Ice Volume Lost

80% of Arctic Sea Ice Volume Lost

Since volume is the most exact measurement, total losses of sea ice in the Arctic are even worse than the satellite pictures would indicate. Much worse, in fact. An 80% loss of sea ice volume since 1979 is a tremendous decline by any account. It shows the ice has grown very, very thin. And more importantly, it shows that we are very close to a time when no sea ice will remain in the Arctic by end of summer.

2012’s Realization of the End of Arctic Sea Ice

How soon? How soon can we expect for there to be no ice left in the Arctic at the end of summer?

And can we expect a total loss of Arctic sea ice at all times of the year within our lifetime? Will the polar sea ice become little more than a myth told at Christmas time? Will the siren song of polar bears and other Arctic creatures, long vanished from the Earth, haunt us in our dreams or the dreams of our children?

Now, those expectations are shattered. Now, you would be hard-pressed to find a single climate scientist who predicts the Arctic summer sea ice will last more than 40 years. A new consensus for ice-free conditions seems to be forming around the 10-20 year mark. And a growing number of scientists are predicting ice-free Arctic seas within the next 3-10 years.

This is the radical change that falls out of the consequences of one freakish year.

But, back to our original question: how soon could it happen?

At the absolute worst case? One year.

Yes. There is a slight but not insignificant chance that all the sea ice could melt away next summer. This event isn’t likely but it is possible if weather conditions like those occurring during 2007 repeat. During that year, 2,500 cubic kilometers of sea ice volume melted away. And this is very close to the present sea ice volume minimum of 3,300 cubic kilometers remaining at the end of 2012. So it is possible, though not likely, that there will be no sea ice left by the end of summer next year. The possibility is low, but not so low as to discount entirely. For sake of argument, we’ll say a 10% chance.

10% isn’t too likely, but it’s enough to keep a climate eye on the Arctic just in case.

Now let’s try to answer the question a little more accurately. Let’s rephrase it and ask how soon is it reasonably likely for summer sea ice to be gone? What’s the best date given current trends?

The answer to this question is actually rather easy. We can track current trends by looking at sea ice volume trends and extrapolating those trends over time. And what we find, doing the math, is that if current melt trends continue, the summer sea ice is most likely to have melted out of the Arctic within the next 4-6 years. We can find this number by averaging sea ice volume declines year-over-year since 2007. When we do this, we find that about 640 cubic kilometers are lost each year, on average. Multiplying this figure by 5 gives us 3,200 cubic kilometers of sea ice remaining, just 100 cubic kilometers below the current minimum.

Since past trends aren’t entirely predictive of future results, we can’t be certain that this event will happen accordingly. An anomalous year like 2007 could wipe out all the sea ice next year or the year after. The sea ice could have been so damaged from 2012’s freak season that each year following will result in more and more melt, a kind of amplifying death spiral until there is no ice left three years from now (a trend that bears out on the exponential graph below). Or, more hopefully, the stunning increase in losses over the past five years will abate due to some unforeseen inertia taking hold — perhaps Greenland providing a kind of fortress for the last of the sea ice. But given the stunning loss trends since 2007 and the added effect of increased sea ice fragility, there is a high likelihood, about 50%, that all the sea ice will be gone by 2018.

The gravity of this prediction should be settling in at this point. I’m not predicting the chance of a summer shower here. I’m providing science-based threat analysis for an event that hasn’t happened in the past 2 million years being a coin toss away within six years. Some scientists are also making this assessment. Deniers, are you listening?

What is important to note is that even my coin toss and average loss analysis may be too optimistic. According to exponential trends — a curve fit over the past 33 years of volume loss — we reach zero sea ice volume by 2015 with a 95% confidence interval for total loss occurring between 2013 and 2018. So my 50% estimate by 2018 may well be low and late (though it takes into account the inherent problems with curve fitting analysis). In any case, you can see this devastating exponential trend here:

At some point, the 90% marker pops up and we don’t really have much reasonable expectation for sea ice to last beyond that point under the current conditions of human-caused global warming and Arctic ice melt trends. Currently, based on the best trends analysis, it’s about 90% likely that summertime Arctic sea ice will be all or mostly gone by 2035. At that point, the only potential source for sea ice comes from Greenland melt and we would hope that volumes of Greenland melt don’t rise to the point of emitting enough ice to temporarily re-grow the summer sea ice.

And an end to Arctic sea ice year-round?

Going back to the potential for events based on exponential trends, it is important to examine entirely what they indicate. What the exponential volume trends are showing is that all sea ice could be gone, year-round, by 2032. This means that in many of our lifetimes (20 years) there could be no Arctic sea ice left — at all.

Back in 2007 these exponential trend graphs bearing out didn’t seem so likely. But, now, it appears that sea ice melt in the Arctic is an exponential, nonlinear event. The result is that it is much more likely that these trend models will serve as accurate future predictions. At this point, it appears far more likely, 25-35 percent perhaps, that amplifying feedbacks in the Arctic will result in ice free conditions for the Arctic Ocean, year-round, by the mid 2030s.

And this is the sad legacy of 2012: the realization of an eminent end of Arctic summer sea ice within, at most, 20 years, and of a likely end to all Arctic sea ice during the first half of this century should human greenhouse gas emissions not abate dramatically and soon.

Today Arctic sea ice extent continued its plunge into record territory. According to measurements provided by the Japanese Space Agency (JAXA), current sea ice extent for August 29th was 3,863,000 square kilometers. This value is 84,000 square kilometers below yesterday’s value and nearly 400,000 square kilometers below the previous record set in 2007.

NSIDC also showed Arctic sea ice continuing its plunge into record territory today. The below image provides a good visual of the lowest sea ice coverage in the NSIDC record:

Arctic sea ice area melt also continued today reaching a new low of 2,570,000 square kilometers, according to reports from Cryosphere Today. This value is 420,000 square kilometers below the record low set in 2011.

Over the past week, all values for sea ice area and extent have pushed to significant new lows. Given the current rates of melt, it appears possible that new records will approach or exceed 500,000 square kilometers below the previous record. By all measures this is a very significant loss of ice for one year.